The volume of a fluid compartment in the body can be measured by placing an indicator substance in the compartment allowing it to disperse evenly through out the compartments fluid and then analyzing the extent to which the substance becomes diluted. The second largest volume is the interstitial fluid which surrounds cells that are not blood cells.
Guide To Intravenous Fluids Stepwards
Measurement of body fluid compartment volumes. At 60 years of age you if male only have 50 body water instead of 60. Measurement of fluid volumes in the different body fluid compartmentsthe indicator dilution principle. Describe the body fluid compartments and explain the methods used for measurement of body fluid volumes. Measurement of plasma volume requires a tracer which is mostly limited to this compartment and this is achieved by using a tracer which binds to albumin. Properties of the tracer and compartment measured blood volume versus plasma volume. Most of the water in the body is intracellular fluid.
The tracers used are the azo dye known as evans blue or t1824 which binds avidly to albumin or radio iodine labelled serum albumin risa. A pie graph showing the proportion of total body fluid in each of the bodys fluid compartments. To be a perfect marker a substance must also not be metabolised. If plasma is x and its volume in body is y then plasmahematocrit100 the volume in body is v. Then make proportion calculation. It takes time for tracer to enter the slow compartments of bone and connective tissue.
This volume is regulated by the movement of free water. The plasma volume is calculated by evans blue technique the proportion of plasma and hematocrit is by centrifugation. The fluid compartment volume. Taken separately there is wide variation in the fat mineral and fluid composition of body tissues. To measure the volume of any fluid compartment within the body you must inject or infuse a marker substance that will equilibrate diffuse freely to a uniform concentration throughout this compartment. If you measure too soon all you will get is the volume of the functional extracellular fluid.
The volume of the plasma is around 3 litres in an average person but the average blood volume is 4 6 litres. The tracers used are the azo dye known as evans blue or t1824 which binds avidly to albumin or radio iodine labelled serum albumin risa. The ecf accounts for the other one third of the bodys. Measuring body fluid compartments. Thus bromine measurements of the ecf volume frequently over estimate the ecf volume. Intracellular fluid 33 231 litres.
As you age you dehydrate. Unfortunately some bromine 82 also distributes into the cells. Body fluid compartments and measurement general physiology duration. Extracellular fluid volume measurement. Measurement of plasma volume requires a tracer which is mostly limited to this compartment and this is achieved by using a tracer which binds to albumin.
Gallery of Measurement Of Body Fluid Compartment Volumes
